- Cellulose fabrics are fibers extracted from plants and transformed into clothing. Fuelled in a large part by promises of higher environmental integrity, cellulose fibers are the fastest growing feedstock of the textile market.
- Companies dominating the market have brought with them systemic problems that have seen primary forests felled, peatlands drained and waste management poorly managed.
- Despite ongoing sustainability issues, the future of the market is promising, experts say, as new innovations and companies have a fighting chance to bring new materials and manufacturing processes to market.
Scientists and companies are looking to a small section of the textile market to address the clothing industry’s threats to climate and ecosystems. Cellulose fabrics are fibers extracted from plants, spun into threads, and shaped into clothing. Fuelled in a large part by promises of higher environmental integrity, cellulose fibers are the fastest growing feedstock of the textile market.
So far, however, companies dominating the market have brought with them systemic problems that have seen primary forests felled, peatlands drained and waste management poorly managed. The future of the market is promising, experts say, as new innovations and companies have a fighting chance to bring new materials and manufacturing processes to market.
“The bare minimum is we got to get off ancient and endangered forests [for textiles]. There’s absolutely no reason the product requires it.” says Peter Wood, senior forest campaigner with Canopy Planet. The advocacy group estimates 200 million trees are cut every year for clothing made from cellulose fibers, a small but growing driver of agribusiness.
A suite of start-ups and established firms are leading a new wave of research and development, experimenting with new ways of creating clothing fibers using everything from alternative trees to fermented waste to recycled cotton. New manufacturing techniques could dramatically reduce textile emissions, which are estimated to equal emissions from the UK, France and Germany. But they face steep hurdles in financing, as large corporations dominate the sector, relying on inefficient materials and manufacturing.
“Now the situation has changed, because the clothing brands are worried about raw material availability and environmental issues at the same time,” says Ali Harlin, a research professor at VTT Technical Research Centre in Finland and a coordinating partner for the EU-backed GRETE project, which funds research into bio-based fabrics.
Petroleum in the form of polyester and nylon make up the majority of textile material, but to achieve the emissions reductions necessary to avoid cataclysmic global warming, fossil fuels need to be left in the ground. Cotton fibers, which make up a third of production, will continue to be significant, experts say, but production has plateaued as climate and labor issues make expansion difficult. Yet demand for new clothes reaches new heights every year, and companies continuously appeal to new customers with lower and lower prices.
This leaves a “cellulose gap,” scientists say, and makes man-made cellulose fibers (MMCFs) like viscose rayon the fastest growing textile market. Companies have championed this group of new plant-based fibers as eco-friendly, because when materials come from plants, those plants can simply be regrown. The fibers themselves can also be biodegradable. But clothing doesn’t sequester carbon for very long, and there’s little oversight of the methods and companies that turn a tree into yarn.
Global fiber production hovered around 110 million tonnes during the pandemic, according to Textile Exchange, a research group that encourages sustainability. That represents almost a doubling of the market since 2009. Other statistics across the industry are hard to come by and verify. Global clothing consumption has been pegged at anywhere from 80 to 150 million items a year, and it has been estimated that for every five garments produced, three go to a landfill each year. Six percent of the materials produced for textiles in 2020 were MMCFs.
Tracing trees
Most cellulose fibers begin as trees on pulpwood plantations that have historically fed material into the pulp and paper industries. It’s this step, acquiring the materials, that contributes the largest share to the textile industry’s emissions. Yet the supply chain is riddled with obfuscation, Peter Wood of Canopy Planet says. “It can be a bit of a black box. These materials are coming from all over the world. They go into this manufacturing process and they come out the other end.”
The top producing company, China-based Sateri, has been linked through its subsidiaries and sister companies to plantations built on drained peatlands in Indonesia. Peatlands are swamplands with highly concentrated carbon. Even though they are a tenth the size of the world’s forests, they store twice as much carbon, according to a global study in Nature. Sateri says they have pledged only to source materials from suppliers who have committed not to clear forest and not to develop on peatland.
Low transparency makes tracking cellulose fibers difficult. Textile Exchange could only identify the source of 42% of the material supply for the participants in their report, which is referred to often by companies and nonprofits. China produced 18% and India produced 5%. Indonesia and Austria both contributed 3%, which likely does not reflect the reality of sourcing, considering the size of plantations and mills in Indonesia.
With little tracking, companies can evade accountability. Sateri’s parent group, Royal Golden Eagle, has also been accused of evading responsibility for cleared peatlands in Indonesia. Another subsidiary was found operating in conservation areas. RGE’s sustainability commitment allows it to develop plantations on peatlands.
Most of the sources of this material come from plantations that were previously set up to accommodate the paper and pulp industry. As a result, it’s dominated by large companies that have already established supply chains that are difficult to change, says Wood of Canopy. Long-term supply agreements and vertical integration put up barriers to deeper change.
Certification programs like the Forest Stewardship Council, have seized the opportunity of a growing market to encourage producers to prove their sustainability commitments. A FSC certification typically states that the materials were sourced from logging operations that supported conservation, forest protection, and Indigenous rights. In 2020, consumers were given the first chance to buy clothing with FSC labels. Twenty-four clothing companies, such as H&M and Masai, have joined the FSC’s Fashion Forever Pact, pledging to make their supply of MMCFs transparent and, eventually, circular.
“The branded side is not so much of a challenge. There’s a lot of really committed organizations. I think it’s the supply chain that’s challenging,” Jeremy Harrison, chief markets officer of the FSC, told Mongabay. Clothing brands are still somewhat surprised when the FSC attends fashion shows, and increasingly they are interested in talking about the variety of materials in clothes that could come from forests.
Textile Exchange, in their 2021 market report, found that just over half of MMCF production came from forests certified for sustainability. The FSC accounted for the majority of these certifications, and the remainder had certifications from the Programme for the Endorsement of Forest Certification, which typically certifies smaller forest owners.
The material from certified forests has also been questioned, as human rights violations have been tied to companies with certifications. The FSC also certifies primary forests. “We do want to remove as much pressure as we can from forests, but we do believe in responsible forest management in the right situations,” Harrison said. The FSC does not certify plantations that were created on land cleared after November 1994, and companies must conserve a minimum of 10% of a representative sample of their management units.
“At the same time, there are many industries that want forest-based products,” says Simone Seisl, a consultant who has worked with Adidas and Textile Exchange. “Do we want to spend it on the construction sector or other products that have a longer carbon sequestration span than creating fibers that only last a few years?”
Turning a tree into fiber
Another RGE subsidiary, Asia Pacific Rayon, last year announced plans to expand its manufacturing facility in Indonesia, which would likely become the largest cellulose mill of its kind in the world. The kind of material, viscose, is the most widely produced cellulose fiber, but researchers say it comes from an inefficient process that exposes workers and ecosystems to toxic chemicals. (APR says they strive for industry best practices in chemical recovery and water waste management.)
Cellulose comprises at most 40% of each tree that is harvested to produce viscose rayon. Carbon disulfide is used to dissolve the wood pulp, but it also can be emitted during the process, endangering workers and people living near plants. In humans, exposure has been linked to neurological impacts, including hallucinations and manic delirium. Close to viscose rayon plants, the carbon disulfide concentrations can be magnitudes above what the WHO recommends in limited exposures. These solvents, in addition to the rest of the tree, are a major waste byproduct that is left to companies to manage.
“You don’t want to have an accident in a viscose plant, because of the possible release of Carbon disulfide,” says Seisl, who authored a chapter on sustainable textiles from MMCFs.
In the past few decades, Lenzing AG, one of the largest cellulose fiber producers, led the development of a process called Lyocell, which uses a less harmful solvent that can be fully recycled. The technology has since been adopted and adapted by other companies, now comprising an eighth of the MMCF market. While the solvents are more expensive, scientists have said it is the most environmentally friendly option on the market. Emissions from lyocell processes are roughly half that of viscose processes.
“Many start-ups are coming up, so it will mean in 10-15 years those will have passed the early phases and start to really grow,” says Harlin. Many of these start-ups brand themselves on sustainability, claiming to be able to avoid many of the issues that afflict the rest of the market.
Kuura, part of the forestry company Metsä Group, aims to perfect a solvent process that uses undried pulp in Finland. Spinnova, using a direct solution process and certified wood pulp, claims to avoid all solvents and sequester more carbon than it emits. BastCore in the US, is working on turning all the cellulose in a hemp plant into textile fibers.
Scaling these products up also entails restructuring supply chains, especially the locations of mills and feedstocks. If it’s expensive and high-emitting to transport materials, companies may prefer to source from the forests where wood pulp installations are already set up. Some pulp mills may also be retrofitted to process alternative feedstocks with new processes.
Wayne Best, an adjunct chemistry professor at the University of Western Australia, stumbled upon microbial cellulose, which has received a lot of attention from larger industry players and advocates. After a winemaker botched a batch of wine, a strange bacterial growth began on its surface. Bacteria seemed to have fed off the sugar and created a pure cellulose on top to act as a flotation device. Harnessing the bacteria’s natural growth, Best’s company, Nanollose, has turned coconut water waste, which is normally waste or made into the jelly-like dessert nata de coco, into a farm for cellulose. Eventually, Best says, other agricultural waste or molasses could become a steady feedstock for clothing fabric.
“Not only is it potentially a lot greener because we don’t have to chop down trees, we don’t have to do wood pulping. It’s also a stronger fiber.” Best says. Nanollose shares joint patents on the technology with Aditya Birla, one of the largest cellulose fiber makers, based in India.
Many of these technologies confront cost barriers as small enterprises, but also due to cheap prices from legacy materials like viscose. Canopy has partnered with clothing brands to formally express interest in buying at least 390,000 tons of next-generation fibers annually, as a way to promise sales for new entrants.
Canopy advocates for 100% recycled cellulose fabrics. Technically speaking, Harlin says, it’s possible to repurpose all discarded fabrics for all current supply. Issues arise when recycled fabrics compete with cheaper, forest-based viscose products. Renewcell, a company based out of Sweden, has secured partnerships with popular brands to create textiles made from 100% recycled clothing fibers. Infinited Fiber, based in Finland, has had similar success with a cotton-like recycled cellulose fabric.
“When you’re able to secure better cellulose content more efficiently from recycled sources, it just doesn’t make sense to be continuing on using virgin fiber,” Wood says. “We have so much textile waste and wood waste; that could easily be going into MMCF materials.”
While there’s a lot of excitement for the innovations in the market, Seisl says it takes additional effort to make sure the energy isn’t extinguished by costs, competitors, or even partner corporations.
“The innovators need these signals, they not only need financial support, but also signals and commitments from the buyers side,” she says.
Related reading: Sustainable fashion: Biomaterial revolution replacing fur and skins
Banner image: Processing abacá fiber, also known as Manila hemp, a species of banana in the Philippines which is used in textiles. Image by Ronald Tagra via Flickr (CC BY 2.0).
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